Promising Sustainable Alternatives Research Articles

Sustainable production of the drug precursor tyramine by engineered Corynebacterium glutamicum.

Tyramine has attracted considerable interest due to recent findings that it is an excellent starting material for the production of high-performance thermoplastics and hydrogels. Furthermore, tyramine is a precursor of a diversity of pharmaceutically relevant compounds, contributing to its growing importance. Given the limitations of chemical synthesis, including lack of selectivity and laborious processes with harsh conditions, the biosynthesis of tyramine by decarboxylation of L-tyrosine represents a promising sustainable alternative. In this study, the de novo production of tyramine from simple nitrogen and sustainable carbon sources was successfully established by metabolic engineering of theL-tyrosine overproducing Corynebacterium glutamicum strain AROM3. A phylogenetic analysis of aromatic-L-amino acid decarboxylases (AADCs) revealed potential candidate enzymes for the decarboxylation of tyramine. The heterologous overexpression of the respective AADC genes resulted in successful tyramine production, with the highest tyramine titer of 1.9gL-1 obtained for AROM3 overexpressing the tyrosine decarboxylase gene of Levilactobacillus brevis. Further metabolic engineering of this tyramine-producing strain enabled tyramine production from the alternative carbon sources ribose and xylose. Additionally, up-scaling of tyramine production from xylose to a 1.5L bioreactor batch fermentation was demonstrated to be stable, highlighting the potential for sustainable tyramine production. KEY POINTS: • Phylogenetic analysis revealed candidate l-tyrosine decarboxylases • C. glutamicum was engineered for de novo production of tyramine • Tyramine production from alternative carbon substrates was enabled.

Thermal Performance of Lightweight Earth: From Prediction to Optimization through Multiscale Modeling

This study investigates the prediction of the thermal conductivity of lightweight earth and raw earth blocks incorporating plant aggregates. Given the high variability of raw materials, it is not currently possible to predict the thermal performance of this type of material before sample production. This is a major obstacle to using these eco-materials, although their use is widely encouraged to improve building performance under evolving regulatory frameworks such as The French RE2020 standard. The incorporation of plant aggregates into earth-based materials offers improved insulation properties without compromising their mechanical integrity, positioning them as promising sustainable alternatives. Mean-field homogenization techniques, including the Mori-Tanaka as well as double inclusion models, are used to develop predictive tools for thermal behavior, using rigorously selected experimental data. The selected methods are particularly relevant. The Mori-Tanaka model appears to be better suited when the proportion of aggregates is limited, whereas the double inclusion scheme proves its worth when a higher proportion of aggregates is incorporated. This study emphasizes the influence of aggregate types and processing methods on thermal conductivity, highlighting the need for precise formulation and processing techniques to optimize performance. This paper demonstrates the relevance of the applied homogenization techniques applied. It enables the real morphology of the materials studied, such as aggregate shape and intrinsic cracking, to be taken into account. It contributes to the advancement of eco-material modeling toward predictive digital twins, with the goal of simulating and optimizing complex material behavior under various environmental conditions.

Agroecological Transformation: Implementation of an Agroforestry System in a Construction Debris Area Focusing on Vegetables Development through Microbial Treatments

Soil microorganisms play an important role on plant development and the homogenization of soil microbiomes is harmful to agri-environments. It is essential that agricultural practices are carried out by taking soil microbiome preservation in consideration. Agroforestry systems are one of the most environmentally friendly agrosystems and its plant diversity directly influences the soil microbiome diversity. In this study, we tested the efficacy of the microbial consortium (MC) obtained from compost and the cyanobacteria Arthrospira platensis (Ap) compared with the application of the vermicompost tea (VT) and bokashi (Bk) in arugula, lettuce, beetroot, and carrot in two seasons in a recently implemented agroforestry system. We aimed to verify if MC and Ap could be new promising sustainable alternatives in vegetables production. The strategy can be broken down into three stages: (1) Green manure management: planting, cutting, griding, and incorporation in the soil, (2) agroforestry system implementation, and (3) treatment application in a completely randomized blocks design. The vegetables yield was measured. Nutritional traits and the plant root system were evaluated for arugula and lettuce. Greater plant yield, nutritional values, and plant root development were observed in the MC-treated plants; Ap and Bk had, in general, similar results. Our data show that both MC and Ap have potential to become a sustainable product for agricultural production.

Shrinkage characteristics of sustainable mortar and concrete with alkali-activated slag and fly ash Binders: A focused review

Alkali-activated binders are emerging as promising sustainable alternatives to ordinary Portland cement (OPC) due to their lower environmental footprint. They offer competitive mechanical properties and enhanced durability, making them attractive options for a wide range of construction and infrastructure applications. This paper is a focused review of key findings related to the shrinkage characteristics of mortar and concrete with alkali-activated slag and fly ash binders. Shrinkage induces nonuniform deformations in mortar/concrete, leading to the development of internal tensile stresses and the formation of cracks. Such cracks may be sufficiently large to facilitate the penetration of harmful substances, which may compromise the integrity of structural elements. Several studies indicated that the combination of fly ash and slag precursors in appropriate proportions produces mortar with favorable shrinkage cracks when compared to mortar with individual binders. This article discusses the influence of the following factors on shrinkage characteristics: binder type, binder proportions, water/binder ratio, binder content, aggregate content, alkaline activator type, and concentration. The article compares the shrinkage of mortar/concrete prepared using mostly alkali-activated slag and fly ash binders and compares their shrinkage response to OPC. Shrinkage types evaluated include chemical shrinkage, autogenous shrinkage, and drying shrinkage. Shrinkage responses reported in this article include the sample curing method and environment as they are known to influence durability, strength, and shrinkage characteristics. In general, mortar/concrete with alkali-activated fly ash and slag experience higher shrinkage rates than conventional concrete with OPC binders. The study further explores shrinkage mechanisms and methods to mitigate shrinkage in alkali-activated binders.

Self‐Sacrificial Template Synthesis of Fe‐N‐C Catalysts with Dense Active Sites Deposited on A Porous Carbon Network for High Performance in PEMFC

AbstractIron‐nitrogen‐carbon (Fe‐N‐C) single‐atom catalysts are promising sustainable alternatives to the costly and scarce platinum (Pt) to catalyze the oxygen reduction reactions (ORR) at the cathode of proton exchange membrane fuel cells (PEMFCs). However, Fe‐N‐C cathodes for PEMFC are made thicker than Pt/C ones, in order to compensate for the lower intrinsic ORR activity and site density of Fe‐N‐C materials. The thick electrodes are bound with mass transport issues that limit their performance at high current densities, especially in H2/air PEMFCs. Practical Fe‐N‐C electrodes must combine high intrinsic ORR activity, high site density, and fast mass transport. Herein, it has achieved an improved combination of these properties with a Fe‐N‐C catalyst prepared via a two‐step synthesis approach, constructing first a porous zinc‐nitrogen‐carbon (Zn‐N‐C) substrate, followed by transmetallating Zn by Fe via chemical vapor deposition. A cathode comprising this Fe‐N‐C catalyst has exhibited a maximum power density of 0.53 W cm−2 in H2/air PEMFC at 80 °C. The improved power density is associated with the hierarchical porosity of the Zn‐N‐C substrate of this work, which is achieved by epitaxial growth of ZIF‐8 onto g‐C3N4, leading to a micro‐mesoporous substrate.

Structure, properties, and fabric applicability of sustainable paper yarn with high washing stability

This research provides an in-depth assessment of two paper yarn variants, examining their structural, functional, and performance characteristics. These yarns demonstrated favorable properties, including suitable linear density, twist, typical cellulosic functional groups as confirmed by Infrared spectroscopy, minimal hairiness, moisture transfer, and creditable mechanical strength. These yarns have flat layered cross-sections and grooved longitudinal surfaces. In addition, a low hairiness index (1.3–1.33) further acknowledged their smooth surface. Their remarkable evenness (15.86% and 7.08%) supported their effective wicking properties. Despite average breaking strength (0.77 cN/dTex and 1.05 cN/dTex) and moderate elongation, these yarns exhibited exceptional water-washing resistance and retained over 89% breaking strength after 15 washes. This study ranks these paper yarns as highly suitable for durable clothing fabrics, providing promising sustainable alternatives in the textile industry.

Lobster-Inspired Chitosan-Derived Adhesives with a Biomimetic Design.

Polysaccharide-based adhesives, especially chitosan (CS)-derived adhesives, serve as promising sustainable alternatives to traditional adhesives. However, most demonstrate a poor adhesive strength. Inspired by the inherent layered structure of marine arthropods (lobsters), a core-shell structure (SiO2-NH2@OPG) with amine-functionalized silica (SiO2-NH2) as the core and oxidized pyrogallol (OPG) as the shell is prepared in this study. The compound is blended with CS to produce a structural biomimetic wood adhesive (SiO2-NH2@OPG/CS) with excellent performance. In addition to thermocompressive curing, this adhesive exhibits a water-evaporation-induced curing behavior at room temperature. With reference to the design mechanism of the lobster cuticle, this microphase-separated structure consists of clustered nanofibers with varying amounts of SiO2-NH2@OPG particles between the fibers. This intriguing microphase structure and its mechanical effects could offer a powerful solution for improving the functional modification of wood composites.

Cellulose nanofiber aerogels modified with titanium dioxide nanoparticles as high-performance nanofiltration materials

Air pollution is a major environmental and public health issue. Each year, large amounts of particulate matter (PM) and other harmful pollutants are released into the atmosphere. Conventional polymer nanofiber filters lack the functionality to capture ultrafine PM. As a sustainable alternative, this work developed titanium dioxide (TiO2) nanoparticle surface-modified cellulose nanofiber (CNF) aerogels for PM2.5 filtration. CNFs were extracted via mechanical disintegration to diameters below 100 nm. The nanofibers were functionalized with 1.0–2.5 wt% TiO2 nanoparticles using citric acid cross-linking. Cylindrical aerogels were fabricated by freezing and lyophilizing aqueous suspensions. Structural, morphological, thermal, and mechanical properties were characterized. TiO2 modification increased density (11.8–19.7 mg/cm3), specific surface area (287–370 m2/g), and Young's modulus (33.5–125.5 kPa) but decreased porosity (99.6 %–97.7 %), pore size (20.2–15.6 nm) and thermal stability compared to unmodified cellulose aerogels. At 2.5 wt% loading, the optimized aerogels achieved 100 % absorption of 0.1–5 μm particulates owing to reduced pore size. Despite enhanced filtration capabilities, the modified CNF aerogels retained inherent biodegradability, degrading over 70 % within one month of soil burial. This pioneering research establishes TiO2 functionalized CNF aerogels as promising sustainable alternatives to traditional petroleum-based air filters, representing an innovative approach to creating next-generation nanofiltration materials capable of effectively capturing fine and ultrafine particulate matter pollutants.

An Evolved Strain of the Oleaginous Yeast Rhodotorula toruloides, Multi-Tolerant to the Major Inhibitors Present in Lignocellulosic Hydrolysates, Exhibits an Altered Cell Envelope.

The presence of toxic compounds in lignocellulosic hydrolysates (LCH) is among the main barriers affecting the efficiency of lignocellulose-based fermentation processes, in particular, to produce biofuels, hindering the production of intracellular lipids by oleaginous yeasts. These microbial oils are promising sustainable alternatives to vegetable oils for biodiesel production. In this study, we explored adaptive laboratory evolution (ALE), under methanol- and high glycerol concentration-induced selective pressures, to improve the robustness of a Rhodotorula toruloides strain, previously selected to produce lipids from sugar beet hydrolysates by completely using the major C (carbon) sources present. An evolved strain, multi-tolerant not only to methanol but to four major inhibitors present in LCH (acetic acid, formic acid, hydroxymethylfurfural, and furfural) was isolated and the mechanisms underlying such multi-tolerance were examined, at the cellular envelope level. Results indicate that the evolved multi-tolerant strain has a cell wall that is less susceptible to zymolyase and a decreased permeability, based on the propidium iodide fluorescent probe, in the absence or presence of those inhibitors. The improved performance of this multi-tolerant strain for lipid production from a synthetic lignocellulosic hydrolysate medium, supplemented with those inhibitors, was confirmed.

Hierarchical biopolymer‐based materials and composites

AbstractThe mass production and disposal of non‐degradable fossil‐based plastics is responsible for alarming environmental and social issues when not managed responsibly. Towards manufacturing environmentally‐friendly materials, biopolymers, that is, polymers synthesized by living organisms, emerge as promising sustainable alternatives as they combine attractive mechanical properties, compostability, and renewable sourcing. In this review, we analyze the structural and mechanical properties of three of the most studied biopolymer classes: cellulose, chitin, and protein beta‐sheet structures. We first discuss the hierarchical structure of the biopolymers and how their rich interaction networks induce appealing mechanical properties. Then, we review different fabrication and processing methods to translate these attractive properties into macroscopic materials and composites. Finally, we discuss a nascent approach, which leverages the direct use of microorganisms, in the form of intact cells, tissues or dissociated biological matter (biomatter), as meso‐scale material building blocks. These non‐ or little pre‐processed biomatter building blocks are composed of the biopolymer structural elements (molecular‐nano scale), but also inherit the higher‐scale hierarchical characteristics. Processing‐structure–property relationships for biomatter‐based materials are discussed, emphasizing on the role of hierarchical arrangement, processing‐induced transformations, and intermolecular bonding, on the macroscopic mechanical properties. Finally, we present a perspective on the role of biopolymers in a circular economy.

Boosting the Transesterification Reaction by Adding a Single Na Atom into g-C3N4 Catalyst for Biodiesel Production: A First-Principles Study

Increasing environmental problems and the energy crisis have led to interest in the development of alternative energy. One of the most promising sustainable alternatives to fossil fuel is biodiesel which is typically produced from the transesterification of refined vegetable oils using a homogeneous base catalyst. However, the current process limitations and steep production costs associated with the use of homogeneous catalysts have limited the global-wide acceptance of biodiesel. Heterogeneous catalysts have been considered suitable alternatives, but they still suffer from low catalytic activity. In this study, by using density functional theory (DFT) calculations, we examined the electronic and catalytic activity of the single Na-doped graphitic carbon nitrides (indicated by Na-doped g-C3N4) toward the efficient biodiesel (acetic acid methyl ester) production via the transesterification of triglyceride (triacetin). Our DFT calculation on reaction energetics and barriers revealed the enhancement of biodiesel productivity in the Na-doped catalyst compared to the pristine g-C3N4 catalyst. This was related to the large reduction of the barrier in the rate-limiting step. In addition, we investigated the acidity/basicity and electron distribution and density of state for the Na-doped and pristine g-C3N4 catalysts to better understand the role of the Na atom in determining the transesterification reaction. This study highlights the importance of the dopant in a g-C3N4 catalyst in determining the transesterification reaction, which may open new routes to improve biodiesel production.

Microalgae Polysaccharides: An Alternative Source for Food Production and Sustainable Agriculture

Carbohydrates or polysaccharides are the main products derived from photosynthesis and carbon fixation in the Calvin cycle. Compared to other sources, polysaccharides derived from microalgae are safe, biocompatible, biodegradable, stable, and versatile. These polymeric macromolecules present complex biochemical structures according to each microalgal species. In addition, they exhibit emulsifying properties and biological characteristics that include antioxidant, anti-inflammatory, antitumor, and antimicrobial activities. Some microalgal species have a naturally high concentration of carbohydrates. Other species can adapt their metabolism to produce more sugars from changes in temperature and light, carbon source, macro and micronutrient limitations (mainly nitrogen), and saline stress. In addition to growing in adverse conditions, microalgae can use industrial effluents as an alternative source of nutrients. Microalgal polysaccharides are predominantly composed of pentose and hexose monosaccharide subunits with many glycosidic bonds. Microalgae polysaccharides can be structural constituents of the cell wall, energy stores, or protective polysaccharides and cell interaction. The industrial use of microalgae polysaccharides is on the rise. These microorganisms present rheological and biological properties, making them a promising candidate for application in the food industry and agriculture. Thus, microalgae polysaccharides are promising sustainable alternatives for potential applications in several sectors, and the choice of producing microalgal species depends on the required functional activity. In this context, this review article aims to provide an overview of microalgae technology for polysaccharide production, emphasizing its potential in the food, animal feed, and agriculture sector.

Biochar production via pyrolysis of citrus peel fruit waste as a potential usage as solid biofuel

Renewable energy sources such as biomass have been proven to be one of the promising sustainable alternatives to fossil fuels. However, using biomass directly as a fuel is less attractive due to its high moisture content, poor grindability, low bulk density, and low energy density nature. Hence biomass can be converted into biochar to overcome these challenges. In this study, biochar was derived from citrus peels biomass by slow pyrolysis over the temperature range of 300–700 °C. The effect of pyrolysis temperature on the quality of citrus peels-derived biochar was examined based on the physical and chemical properties obtained from various analyses. The citrus peels biomass and biochar were characterized by means of higher heating value (HHV) analysis, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX), Fourier transform infrared ray (FTIR) analysis, proximate and thermogravimetric analysis. Based on the characterization results, the potential usage of the derived biochar as a solid fuel was discussed. Results obtained from the pyrolysis experiments indicated that a lower pyrolysis temperature produced a higher char yield. The carbon content and energy content of biochar were found to be increasing with pyrolysis temperature. Biochar produced at 500 °C presented the best fuel properties by having the highest value of HHV and carbon content. The results from this study provided great insights into biomass waste reutilisation to generate value-added biochar for renewable energy production in Malaysia.

Current knowledge and future perspectives of the use of seaweeds for livestock production and meat quality: a systematic review.

The effects of dietary macroalgae, or seaweeds, on growth performance and meat quality of livestock animal species are here reviewed. Macroalgae are classified into Phaeophyceae (brown algae), Rhodophyceae (red algae) and Chlorophyceae (green algae). The most common macroalga genera used as livestock feedstuffs are: Ascophyllum, Laminaria and Undaria for brown algae; Ulva, Codium and Cladophora for green algae; and Pyropia, Chondrus and Palmaria for red algae. Macroalgae are rich in many nutrients, including bioactive compounds, such as soluble polysaccharides, with some species being good sources of n-3 and n-6 polyunsaturated fatty acids. To date, the incorporation of macroalgae in livestock animal diets was shown to improve growth and meat quality, depending on the alga species, dietary level and animal growth stage. Generally, Ascophyllum nodosum can increase average daily gain (ADG) in ruminant and pig mostly due to its prebiotic activity in animal's gut. A. nodosum also enhances marbling score, colour uniformity and redness, and can decrease saturated fatty acids in ruminant meats. Laminaria sp., mainly Laminaria digitata, increases ADG and feed efficiency, and improves the antioxidant potential of pork. Ulva sp., and its mixture with Codium sp., was shown to improve poultry growth at up to 10% feed. Therefore, seaweeds are promising sustainable alternatives to corn and soybean as feed ingredients, thus attenuating the current competition among food-feed-biofuel industries. In addition, macroalgae can hinder eutrophication and participate in bioremediation. However, some challenges need to be overcome, such as the development of large-scale and cost-effective algae production methods and the improvement of algae digestibility by monogastric animals. The dietary inclusion of Carbohydrate-Active enZymes (CAZymes) could allow for the degradation of recalcitrant macroalga cell walls, with an increase of nutrients bioavailability. Overall, the use of macroalgae as feedstuffs is a promising strategy for the development of a more sustainable livestock production.

Synthesis of poly-3-hydroxybutyrate (PHB) by Bacillus cereus using grape residues as sole carbon source

ABSTRACT Polyhydroxyalkanoates (PHA) are bacterial polyesters that have been described as one of the most promising sustainable alternatives to petroleum-based plastics. A major challenge for PHA to become market-competitive, is to decrease the associated production costs. According to several studies, about 20–50% of the total production costs is attributed to the raw materials and therefore, the use of different types of organic residues have been evaluated as substrates for the microorganisms. In this study, the strain Bacillus cereus ATCC 14579 was cultivated in shake flasks using a defined medium and pretreated grape peel as sole carbon source. The pretreatment of the grape peels was performed by a hydrolysis step with diluted sulfuric acid yielding up to 52.9% (w/w) of total sugars from the dry residue. PHB extraction using dry and wet biomass was performed and evaluated showing up to 3.7-higher yields when using the latter. PHB accumulation of 18.79% (w/w), corresponding to 0.53 gPHB/L, was achieved using the grape peel hydrolyzate at 72 h of cultivation. Eventually, the possibility of producing PHB by the use of non-treated lignocellulosic biomass (LCB) with high contents of fermentable sugars is presented as an interesting alternative to be optimized and projected for sustainable bioplastic production processes.

Graphitic carbon nitrides: Efficient heterogeneous catalysts for biodiesel production

Abstract Biodiesel remains one of the most promising sustainable alternatives to fossil fuel-derived energy; however, current process limitations and steep production costs associated with the use of homogeneous catalysts have limited global-wide acceptance and adoption. While heterogeneous catalysts have been put forth as suitable alternatives, they suffer from numerous drawbacks including high metal content and cost. As such, the search for novel and inexpensive alternatives is currently underway. Graphitic carbon nitride macrostructures have been widely investigated for photocatalytic applications yet their role in driving chemically-catalyzed reactions remains relatively unexplored. Herein, we synthesized and investigated the use of bulk, fiber, acid- and thermal-treated carbon nitrides as heterogeneous catalysts for the transesterification of canola oil to biodiesel. A conversion of 96% was achieved using 1 wt% catalyst loading, a low oil to methanol ratio of 1:24 and a reaction temperature and time of 150 °C and 3 h, respectively. Carbon nitrides offer a high thermal stability, cost effective and metal-free alternative to the many proposed metal-containing heterogeneous catalysts for biodiesel production, while maintaining high biodiesel conversions of >90%.

Methoxy groups reduced the estrogenic activity of lignin-derivable replacements relative to bisphenol A and bisphenol F as studied through two in vitro assays

Bisguaiacols are promising lignin-derivable alternatives to bisphenol A (BPA), but limited bioassay data are available on their estrogenic activity (EA). Herein, we investigated the estrogen receptor alpha (ERα)-mediated EA of six newly synthesized bisguaiacols, which differed in the number and location of methoxy substituents, through in vitro assays: MCF-7 cell proliferation and VM7Luc4E2 transactivation. The six bisguaiacols had undetectable EA at concentrations less than 10−7 M, most importantly, with significantly lower EA than BPA over an environmentally relevant range of 10−10–10−7 M. Adding a single methoxy group led to significant reduction in EA in all cases, relative to BPA and one petroleum-derived BPA analogue (bisphenol F, BPF), and the incorporation of more methoxy groups had subtler, but pronounced, impacts on either ERα binding or MCF-7 cell proliferation. In short, the six lignin-inspired bisguaiacols presented herein are viewed as promising sustainable alternatives to BPA and BPF.

Dynamic Climate Analysis for early design stages: a new methodological approach to detect preferable Adaptive Opaque Façade Responses

ABSTRACT Mainstream design approaches for low-energy buildings make use of highly-insulated building envelopes. However, if facades are always blocking energy exchange, the climatic resources surrounding the built environment might remain untapped or issues like overheating could arise. By reducing energy demand or improving indoor comfort, adaptive opaque facades are considered a promising sustainable alternative. The usual approach for designing adaptive facades relies on detailed simulations of specific facade components. Such technology-oriented approaches tend to be incompatible with the early-stage design process and do rarely make a conscious analysis of the potential climatic resources, which could result in sub-optimal facade adaptation strategies. This paper presents a new methodological approach called Dynamic Climate Analysis (DCA) and shows that it is possible to narrow down the preferable adaptive opaque facade responses at early design stages by extracting relevant transient information from weather files. Users only define the location, geometry and placement of the facade. It was concluded that DCA represents a broadly useful early-stage design decision support because of its ability to estimate the proportion of preferred adaptive thermal behaviours without proposing defined technological solutions. Therefore, DCA is an effective approach to test the potential application of upcoming responsive technologies in specific built contexts.

Development of ethylene-vinyl acetate copolymer/graphene oxide nanocomposites for crystalline silicon photovoltaic modules

Renewable sources of energy, such as solar cells, stand out as promising sustainable alternatives, given the growing world energy demand. The crystalline silicon photovoltaic (PV) modules are the most used in the conversion of solar energy into electricity. These modules are subject to weather conditions that may cause degradation of the ethylene vinyl acetate copolymer (EVA) encapsulant (cross-linked EVA copolymer), affecting the efficiency, stability and service life of the PV conversion. In this work, the development of an encapsulant was performed, based on the addition of graphene oxide (GO) to EVA encapsulant forming the nanocomposite (EVA/GO), in order to improve the stabilization against photodegradation. Nanocomposites with GO concentrations wt. %: 0.25%, 0.50%, 0.75%, 1.0% and 2.0% were characterized by: Fourier transform infrared spectroscopy by attenuated total reflectance (ATR-FTIR) thermogravimetry (TG), and differential scanning calorimetry (DSC), before and after they underwent accelerated aging processes in Weather-Ometer and UVB rays chambers. In general, the addition of GO minimized EVA encapsulant degradation. Only the encapsulant with GO concentration of 0.25 wt% was shown as promising for photovoltaic modules, since the transparency of the films with higher concentrations was impaired.

Assessing the environmental and economic sustainability of autonomous systems: A case study in the agricultural industry

Abstract While autonomous machines are considered as a new opportunity to augment safety, reliability, productivity, and efficiency, the actual environmental and economic sustainability performances of many autonomous systems remain yet to be quantified. The present research aims to fill part of this gap by evaluating the life cycle impact and cost of autonomous solutions in the agricultural industry. Comparative life cycle assessment (LCA) and life cycle costing (LCC) are carried out on a real-world case study putting in parallel a robotic electric lawn mower (autonomous solution) and conventional – gasoline- and electricity-powered – pushing mowers (human-operated counterparts). Results are interpreted in terms of global warming potential and total cost of ownership. While the autonomous system already appears to be a promising sustainable alternative, discussions and quantitative insights are also provided on the conditions that would lead to further environmental savings and economic profit for this autonomous solution.